Digital radio processing often encompasses a digital processing component which under the control of a stored program performs radio signal processing functions which are normally the province of analog circuits in analog radio processing systems. Analog functions such as frequency selection, filtering, demodulation and channel processing are now performed digitally under the control of a stored program. Using a stored program not only allows radio signals to be processed under control of instructions; it readily facilitates flexibility in the performance of other system processes related to the use of signal processing that are not normally considered the processing of radio signals. Many system specific characteristics, such as frequency, channel bandwidth, modulation type, channel coding and source coding may be flexibly accommodated under control of such a stored program. Digital radio processing permits a variety of controls and operational features not available or feasible in radio systems using analog processing